The invention relates to a process and a device for determining the adhesion of an individual fibre embedded in a synthetic material matrix. The process and the device are based on the carrying out of a drawing experiment, in which the fibre is drawn out of the synthetic material matrix and the associated force-distance diagram is simultaneously registered.
The mechanical characteristics, such as e.g. strength, the modulus of elasticity, or the dampening behaviour of fibre-reinforced synthetic material are paradigmatically determined by the adhesion strengths of the fibres in the synthetic material matrix. The adhesion force of the fibres can be measured directly by the drawing experiment referred to above. It is important therein that this measurement is of a single fibre. Otherwise, only undefined average values of relatively low informational content would be obtained.
One might think of preparing test samples of fibre-reinforced synthetic materials in such a manner that individual fibres project out of the synthetic material matrix, which are then drawn out of the test sample in one drawing experiment. Apart from the fact that such technology of preparation is difficult and is tied to a relatively high cost, the basic problem consists in that in the preparation of the test samples the adhesion of the fibres, i.e. the magnitude to be investigated, is influenced and changed in an uncontrolled manner, so that systematic errors of measurement result and the measurement is no longer representative. In carrying out drawing experiments of this kind, therefore, the following aims are considered to be priorities within the framework of the present invention:
a) The test sample preparation or the manufacture of the test sample bodies should take place as simply and quickly as possible.
b) Test sample bodies manufactured under identical conditions must yield reproducible results of measurement.
c) In the test sample preparation, the chemical and physical characteristics of the fibre and of the synthetic material matrix responsible for the adhesion forces should be controlledly variable.